In the wide range of area including fabrication of semiconductor IC such as LSI and display surface of FPD, and fabrication of circuit substrate such as magnetic head, importance of high-precision processing technology is increasing. Photo fabrication being mainstream of the high-precision processing technology for forming minute device or minute working means an art for fabricating various precision components like semiconductor packages by coating photosensitive resin composition called as “photoresist” (hereinafter, it may be abbreviated as “resist”.) on the surface to be worked to form a coating, patterning the coating by developer, and forming a pattern with the above patterned coating as a mask by carrying out the electroforming (specifically, chemical etching, electrolytic etching, electroplating, or combinations thereof).
In recent years, with a downsizing of electronic devices, high-density mounting technology of semiconductor packages has been developed. In order to mount the packages on the electronic devices like LSI, multiple-pin thin-film mounting method is carried out for providing connecting terminals consisting of projection electrodes onto the surface of the support such as substrate. In the multiple-pin thin-film mounting method, connecting terminals consisting of bumps which projects from the support, or another connecting terminals consisting of posts called as “metal post” which projects from the support, and solder ball formed thereon are used.
The bumps and the metal posts are, in general, made in accordance with the following procedures. Namely, first of all, an around 3 μm or more thick of thick photoresist layer is formed on a substrate as the support; through the steps of exposure and development, resist pattern of which width is usually 5 μm or more is formed; then, on the surface of the substrate exposed from the pattern's concave portion (a section which is not covered by the resist, it may be called as “non-resist section”), a conductor such as copper is filled by plating or the like; and finally, the resist pattern around the conductor is removed, to form the bumps and the metal posts (refer to Patent document 1).
In the above-described method, the 3 μm or more thick of exposed thick photoresist layer is needed to be developed. However, when film thickness of the resist becomes thicker, scum tends to be caused; thereby shape of resist pattern tends to be deteriorated.
So as to inhibit cause of the scum and to form favorable resist pattern, a method by adding surfactants to the developer is known (refer to Patent documents 2˜4). For example, Patent document 2 discloses a method as follows: by using a developer consisting of tetramethyl hydroxide aqueous solution to which 0.01˜0.5 weight % of aqueous nonionic surfactant and 0.004˜0.4 weight % of a particular cationic surfactant are added, 1.5 μm thick of positive-type photoresist film is developed, to obtain a high contrast resist profile. Moreover, Patent document 3 discloses a photoresist developer consisting of alkaline aqueous solution containing nonionic surfactant and cationic surfactant at the concentration of 10˜5000 weight ppm in total. Further, Patent document 4 discloses a method which is capable to form a favorable pattern without causing scum and film's residue as follows: 1.3 μm thick of the resist film is developed by using developer consisting of an aqueous solution of an organic quaternary ammonium compound containing 500˜50,000 ppm of anionic surfactant having a particular structure.    Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No. 2005-134800    Patent Document 2: Japanese Patent Application Examined No. 6-3549    Patent Document 3: JP-A No. 2002-169299    Patent Document 4: Japanese Patent No. 2589408